Let’s do a small experiment.

Suppose I present you with a number sequence: 2-4-6. I tell you that the sequence follows a certain rule, and the task is to calculate the underlying rule. You are allowed to present other strings of three numbers, and ask whether or not these new strings meet the rule.

If you’re like most people, your first instinct is that the rule is “ascending even numbers” or “numbers increasing by two,” and so you guess something like: 8-10-12, and to this I say, “Fits the rule.”

Now your confidence rises. To confirm your hypothesis, you test out just one more possibility, just as due diligence, something like, 20-22-24. Again, “Fits the rule.”

Now you have concluded, “The rule is to add two to the last number,” and you declare your answer. Unfortunately, that is not the rule!

How can this not be the rule? “But it’s so obvious,” you think.

Can you tell me how you actually came to the conclusion about the rule? Most likely, you had a hypothesis and you ran a couple of experiments to confirm it. You felt that “add two to the last number” is the correct rule, and ran tests to confirm this rule.

And I don’t blame you for that. It is not natural for us to formulate hypotheses, and then test various ways to prove them false. Instead, it is far more likely that we will form one hypothesis, assume it is true, and only seek out and believe information that supports it. Most people don’t want new information, they want validating information.

Sir Karl Popper (regarded as one of the 20th century’s greatest philosophers of science) believed that the only way to test the validity of any theory is to prove it wrong-a process he labelled Falsification.

And it turns out we’re quite bad at falsification. Mostly because it is unintuitive, and it doesn’t come naturally to us. Let me explain with the same example.

To solve the number-sequence problem, let’s try a very unintuitive approach this time. Instead of trying to confirm our hypothesis, let’s try to disconfirm it.

The hypothesis is, “Add two to the last number,” so naturally a sequence like 7-9-11 won’t fit the rule. But if you present me with it that, I would say, “Fits the rule.” Wow! Did your hypothesis just get debunked so easily?

Let’s get wild now. How about 7-8-9? “Fit the rule.” How about 15-199-1123? “Fit the rule.” Getting weirder! I’m sure you have several hypotheses about the rule in your head by now. How about 12-16-29? “Fits the rule.” Okay. How about, 8-12-10? “Doesn’t fit the rule.” Interesting! How about negative numbers? (-2)-(-4)-(-6)? “Doesn’t fit the rule.” How about, (-10)-(-6)-(-1)? “Fits the rule.”

Most likely by now you know of a lot of rules that are very likely incorrect. So what’s the rule? Is it, The next number must be higher than the previous one?

8-10-12 does fit the rule, it’s true, but so does 7-9-11, and 12-16-29. The only way to win the game is to guess strings of numbers that would prove your beloved hypothesis wrong-and that is something each of us is constitutionally driven to avoid.

“The first principle is that you must not fool yourself and you are the easiest person to fool.” — Richard Feynman

Adopting falsification as a method is easier said than done. We all need safety and comfort, both physical and intellectual. Above safety we need certainty, and falsification in itself means that you can never be certain of anything.

Falsification implies that you have to always test your ideas, claims, and beliefs, and have the mental discipline to update whenever you are proven wrong.

This method can be adopted in two steps:

  1. For any belief you have or any claim you make, ask what it would take for you to change your mind. Be as specific about that evidence as possible.
  2. Seek out that evidence, and be willing to change your belief if you find it.

We all are plagued by lots of hidden biases when it comes to making decisions or sheltering beliefs. All of that can be put in check if you adopt the falsification method.

On top of that, you also will be able to see your attitude change - you’ll become more open-minded, and less likely to be dismissive of others, or other sources of information.

Falsification, if mastered, has a lot of upside and zero downside.

Weaker opinions are easily destroyed by this method. On the other hand, the more your efforts are unable to devalue your opinion, the stronger your opinion gets.

It also forces you to do the hard work to have an opinion, and be able to argue better against your view than the smartest guy who holds that opposite view. This only makes you more persuasive.